The 10-day forecast is a prediction of the weather extending 10 days into the future (with varying degrees of accuracy). However, when Cueball checks the forecast for his local area, it apparently predicts progressively extreme lightning storms, a plague of insects, what appears to be The Rapture, and the appearance of the anti-Christ. Upon the anti-Christ (or perhaps Woden or Mothra) appearing, the forecast breaks up into static and nothingness with the day stuck on Tuesday, meaning that the world has ended.

When asked about this, Megan casually explains that Cueball put a minus (-) sign in front of his ZIP code. A ZIP code is a numeric postal code used in the United States, but many more countries use similar systems. As ZIP codes are tied to a geographic location, it is also often used to specify a local region for the purposes of weather reports.

Many computer systems that let the user write in a number only work with certain numbers (such as positive numbers). Numbers the system is not designed to work with, such as negative numbers, may lead to errors or unpredictable behavior (or, more often, the system will just refuse to proceed until you input a valid number). When this happens with the number of a video game level, it can result in data of another type being loaded, creating a level with a corrupted or physically-impossible landscape; this is sometimes known as a "Minus World".

Megan states that you get this result for any negative zip code. This may be an "error" deliberately put in by the programmers designing the system, to freak out people who make a mistake.

Cueball on the other hand reacts as if this negative zip code actually represents an actual geographical location, or a real-life Minus World, and that the weather forecaster is indeed showing an accurate forecast for the (corrupted) area. Since Megan stated that the forecast is always like that for these zip code Cueball expresses that he would never move there.

In the title text, Megan agrees with Cueball's desire not to move to that ZIP code area, the punchline being that her reason is not to avoid the apocalypse, but to retain access to Amazon Prime, which shows that her priorities are amusingly warped. The service Amazon Prime is provided by Amazon, where the user pays a flat annual fee and in exchange they get access a number of "enhanced" Amazon services, including free two-day shipping, free access to a library of streaming videos, and the ability to borrow books.

[A caption is written above ten small panels in two rows. In each panel is an indication of the weather. Below each panel a label tells which day it is referring too.]

Your 10-day forecast:

[A yellow sun.]

Today

[Two gray clouds in front of the sun.]

Tomorrow

[Thunderstorms, with three gray clouds and a single lightning bolt.]

Friday

[Extreme thunderstorms with many large gray clouds and seven lightning bolts]

Saturday

[A swarm of insects, with one large black one close by and seven others close enough to discern details. The rest of the swarm is grayed out and just shown as small dots behind these other eight insects.]

Sunday

[Images of distorted, people with very long legs. One Megan, one Cueball and someone in the background.]

Monday

[A humanoid figure with two large horns or a winged helmet silhouetted against a bleak red background. The ground beneath the figure is black.]

Tuesday

[Grey static]

Tuesday

[Black screen]

Tuesday

[Black screen]

Tuesday

[Megan has entered the panel and stands behind Cueball looking at his laptop over his shoulder. She points to the screen. Cueball holds his hand to his chest.]

Megan: ...Oh! You typed a minus sign in the ZIP code. The negative ZIP codes are all like that.

Discussion

You might think Tuesday's image could be anything, even cacti. I did, until I read these comments and zoomed in. Now I think it looks like Jamiroquai's mascot, the guy with the horned helmet. -- 101.162.84.101 (talk) (please sign your comments with ~~~~)

Can't believe multi mention of apocalypse but no mention of my first guess (due to -), that place below.
Monteletourneau (talk) 07:00, 1 August 2013 (UTC)

Any possible significance of people seeming having longer legs that usuall on "monday" frame? Also, why should that "tuesday" figure be antichrist? Looks more like Loki to me (although if it SHOULD be Loki he would probably look even more similar). And "sunday" frame looks more like Bees that Locust, but it's true I never heard of plague of bees :-). (On the other hand, if Plague of locusts would be referenced, one would expect the other plagues as well.) Also note that if that should reference Christian Apocalypse, it should include more horses. -- Hkmaly (talk) 09:16, 31 July 2013 (UTC)

I think the "legs" thing is indicating they're floating up due to the Rapture. --Druid816 (talk) 10:26, 31 July 2013 (UTC)

It's also possible that we're looking at a reference to the Doctor Who episodes "The Impossible Planet" and "The Satan Pit" in which the Tenth Doctor encounters "the devil" on the remnant of a planet orbiting a black hole. If that's the case, we could be looking at some spaghettification on Monday. --NHBradson (talk) 16:41, 5 August 2013 (UTC)

To me he looks more like Hellboy with horns (in apocalypse mode). His right hand seems to also be larger than his left.37.130.227.133 17:02, 5 August 2013 (UTC)

I think that it's actually Megan that says the title text, and not Cueball, mainly because the title text is agreeing with what Cueball said ("Oh, definitely not"). If Cueball were to confirm his own sentence, it wouldn't make sense. greptalk11:20, 31 July 2013 (UTC)

Isn't Sunday a plague of flies? And, judging by the curvature of the earth (I assume) on Tuesday One, wouldn't the character be the size of Galactus? With horns like Galactus? I think it makes sense that it's Galactus. And Monday is just a weird day, just like in my zip code. 67.60.145.86 13:36, 31 July 2013 (UTC)

I assume he's just standing on a hill.153.31.113.20 18:53, 31 July 2013 (UTC)

Not so off-the-wall. The zip code is an American-only thing. Might be worth a mention for non-American readers. Vyzen (talk) 16:21, 31 July 2013 (UTC)

Strongly disagree with that statement. I live in Israel and we have and use zip codes. 95.35.56.169 17:42, 31 July 2013 (UTC)

Well, here in the UK we use Postcodes that are alphanumeric in nature but pretty much have the same purpose behind them. Although thanks to US imports on TV/films I think most people know that the US call theirs ZIP Codes, even if not that it's a simple number (like I believe most of European postcodes are). However, it doesn't harm to give the link referencing it (as has been done) for anyone who really doesn't know or just appreciates a push towards a bit of Wikicreep. (Which I've just self-inflicted on myself by reading down the Postcode article... Forsooth! Hoist by my own petard!) 178.98.215.19 19:19, 31 July 2013 (UTC)

Uhhh, your Postcodes are a horror for programmers, just because the length vary. The first official implementation for this was during WWII in Germany, the UK did implement this in the range of 1959-1974, and the US did start this system in 1963. But there are still many countries not using this system (like Ireland), which is just a double horror for programmers.--Dgbrt (talk) 20:18, 31 July 2013 (UTC)

Start with "m/(\w+) (\w+)/" and then subdivide into branches according to $1's further matching? At each stage checked for more specific validity (and even existence!). If not that, "m/[A..Z]{1,2}\d{1,2}[A..Z]? \d[A..Z]{2}/i" should work if you want just a single test (with ()s around elements for the geographic validation checking part). Ok, so it's not "\d{howevermany}", then check it exists on the database, but it'd do for starters, and personally I relish such programming challenges... ;) 178.98.215.19 11:36, 1 August 2013 (UTC)

Did anyone else try to put in a negative zipcode because of this? I think Google should use this as one of the easter eggs they're so fond of. 138.162.8.57 16:14, 31 July 2013 (UTC)

at weather.com a negative ZIP code gets you a "can't find" type result with Cancun, Mazatlan and Amsterdam offered as suggestions for where you were interested in. (I tried ZIPs from 10012 to 98072, same result for all I tried). Google Maps just ignores the negative and gives correct results. 67.51.59.66 17:48, 31 July 2013 (UTC)

Does anyone agree that Randall is playing with the fact that 10day forecast are very inaccurate. We can trust 3, max 4 days of accuracy. After that, is pretty meaningless since the divergence of the models is a likely scenario. No?cinico (talk)

I often say that the "five day forecast" is fiction after two days. --Mr. I (talk) 19:17, 31 July 2013 (UTC)

The forecast shows much more than expected from a normal "weather forecast". I like that. Sebastian --178.26.118.249 19:34, 31 July 2013 (UTC)

What happens to time, when the world ends? It is a 10-day-forecast. That coincides with 10 image frames. We have the days of the week at the bottom of the frames, which are an independent scale, because there is more than one frame for Tuesday. Interpretation/Assumption: 10 days (the forecast) is subjective for the people being in each location (here: ZIP code). Days of week and generally dates are a global reference time. So in these hells time locally stretches for eternity and this day will never end. But from an outside view time goes on normally.
Megan says they are all like that. That does not sound like it would be a special occasion to be there, when the world ends, or having found a ZIP number, where the world ends some days from now. Possible solution: Like a function with several poles the world could end at every location with negative ZIP about every week. Sebastian --178.26.118.249 19:49, 31 July 2013 (UTC)

The fact that the "negative ZIP" universe ends while the normal one keeps going, points again to my theory (above) that this is a reference to Donnie Darko, Frank the rabbit (not the antichrist), and where negative ZIPs are for Tangent Universes. However I'm not a Donnie Darko expert (I think I started to understand it now reading that website, and the one time I watched it was in theaters...) and I'm not able to provide a theory for the bees/locusts... --Danroa (talk) 12:47, 1 August 2013 (UTC)

What about negative people, or negative areas where everyone is negative. Doom and Gloom, end of the world type of deal. Seems like a lot of negative people are always talking about the end of the world, and that negative zip code and what's occurring sounds exactly like how the end of the world is pictured. She says all negative zip codes are like that. -- Glitch (talk) (please sign your comments with ~~~~)

"Megan, however, assumes that the negative zip code represents an actual geographical location, and that the weather forecaster is showing an accurate forecast for the area. She further states that, since all negative zip codes produce similar forecasts, that all negative zip codes represent actual geographical locations for which the weather is like that."

I think that's reading too much in the comic; I wouldn't say she's making such an assumption. 84.197.94.196 21:11, 1 August 2013 (UTC)

Is it necessarily a reference to the rapture? I mean, it seems to me that it could be poking fun at the twilight zone, or maybe parodying horror in general. --the amazing alixetiir (talk) 03:18, 2 August 2013 (UTC)

Is it just me or can you kinda see a demonic face with horns in the static for the second "Tuesday"? --208.84.194.188 03:24, 2 August 2013 (UTC)

It might be related to something someone said above, about long-term forecasts being inaccurate, the impossible nature of the integer (entered in the zip code) might cause the prediction function to go wild. This inaccurate forecast theory would be supported by how the first few days appear normal, where as the further it goes, the crazier it gets. My rendition of the comic would be that when entering a negative zip code, being an impossible value, it would render a prediction for a chaos-filled world. No end-of-the-world, no Antichrist, just pure chaos. Think of being present in a day where such a massive lightning-filled lightning storm goes on (zapping the ground every few moments), followed by a day where hoards of bees come by in masses, followed by some impossible to imagine occurrence that causes people to be so deformed (as far as you can tell, the could be deformed like that all the time in the chaotic universe). Then the day after some mysterious creature shows on the horizon, like in a horror film... I think this is supported by the Monday and (fire) Tuesday panels showing a bit too specific scenarios, as if someone took pictures of the occurrences.
But I do come to think it's either the prediction function going haywire the further it gets, or that Minus World thing 38.108.195.69 mentioned (which isn't very far-fetched). After all, Randall knows his computing and maths and it would be assumed he simply made references to such instances of giving a function wrong input and receiving a crazily unpredictable output. 79.179.106.35 08:34, 2 August 2013 (UTC)

The person on the second Tuesday is supposed to be the Antichrist? I thought it was just a girl with really long pigtails like some kind of Pipi Long-stocking sort of thing where they have a mind of their own or something. I also thought the gravity was just turned off on Monday. I had the feeling There was some kind of apocalypse thing going on though.72.193.171.120 08:05, 4 August 2013 (UTC)

The hover text mentioning "...they don't have Amazon Prime" is probably a comedic extrapolation that, since there are no negative prime numbers, there couldn't be an Amazon Prime in a negative zip code. 24.217.105.50 05:49, 5 August 2013 (UTC)

Personaly i see one of the angels from evangelion on earth surface into the Tuesday box. Not seeing this obvious référence in this thread make me write amoung far more clever comentaries... -- 82.245.232.105 (talk) (please sign your comments with ~~~~)

At least in part, this is a Jurassic Park reference. In the book, they discuss how the origin of chaos theory began with the inability to predict weather beyond three days. Given that the weather gets crazy after three days, this just makes sense! 75.75.1.95 (talk) (please sign your comments with ~~~~)

IMO the Tuesday guy is obviously HellBoy in his stick-man form as the world is destroyed. I do not see his crown however.--108.162.219.18 20:45, 21 May 2014 (UTC)

I þink it'd be beſt to rewrite ðis article wiþout ſtatiŋ ðat it's probably juſt a prank by ðe programmers- it defeats ðe humor too muĉ, and it'd be more entertainiŋ(/horrifyiŋ) if it is properly interpreted to be a correct forecaſt, just of ðe wrong place. Beſides, xkcd has ʃown us ðat its world is a bit more bizarre and ſupernatural ðan ours on /more/ ðan one occaʒon; haviŋ a world where weaðer is simple, predictable, ðere aren't ſwarms of fleʃ-mites, water (I aſſume ðat's just normal O^2H) falls from ðe sky, and days don't repeat after cataſtrofic occurrences like ðe recent Siksþ Return in Hexadectober 1443+194i Hppavilion1 (talk) 01:59, 14 September 2016 (UTC)

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